DALLAS - It was the worst phone call Sophia Silbas has ever gotten in her life.

Her 14-year-old son, Kevin Crockett, had been robbed and pistol-whipped by masked men. One of the robbers fired a gun, but the bullet went past him.

“He shot the gun and said that it wasn’t a joke,” Kevin said. “He was going to shoot me.”

It took an agonizing 90 minutes and four desperate calls to 911 for Dallas police to show up.

“An hour and a half could be somebody's life,” his mom, Sophia Siblas, said.

There's just not enough officers to do the job. More than 300 officers have left the department since October. Seventy-four more officers have already put in the paperwork, notifying the Dallas Police Department that they plan to leave.

The department’s down to about 3,150 officers, roughly 500 fewer than the department had six years ago.

Manpower shortages are causing response times to spike all across the city.

Stokes says there was a breakdown in how the call was handled. He says a supervisor should have gotten involved and ensured that the call was answered quicker.

There are changes in the works. To combat rising response times, Stokes has ordered the department's daytime crime response teams at all of seven stations to answer calls. Plainclothes deployment at two stations has been put back in uniform during the day.

“We have to change, and sometimes we have to change the way we do things,” he said. “With the loss of manpower, we have to do things differently.”

He says pulling crime response teams and deployment comes at the cost of stopping crimes before they happen.

“There's going to be some trade-offs,” he says. “The problem is that those trade-offs are going to have consequences.”

Deployment teams, for example, frequently target known burglars before they can burglarize homes or businesses.

Crime response teams often handle drug house complaints. Because there’s a nexus between drug houses and property crime, that helps prevent burglaries and thefts. They also help the department keep up with arresting those who are wanted on warrants.

On that day, Kevin had been dropped off by the bus. He attends a collegiate academy and starts high school in the fall.

He was walking home when he was robbed at Treetop Lane and Tioga Street in south central Dallas. Kevin ran to his neighbor’s home. That’s when he saw the two men. One of them had a gun. He was too afraid of what would happen if he ran.

One of the robbers grabbed him and twisted him his fingers. His fingers are bandaged from the injury. The other one hit him in the head with the gun.

“I fell to the ground and they took my phone and ran,” Kevin said.

He ran to his neighbor’s house for help.

Sammy Smith, his neighbor, called 911 at 2:56 p.m.

“I told him that it was a 14-year-old kid and that he was shot at and that he was hit in the head with a pistol,” Smith said.

He called again at 3:21 p.m. when the police still hadn’t arrived. He says at one point, an operator told him that there were other calls holding in front of theirs and that officers would be there as soon as possible.

Silbas’ cell phone logs show that she called the police at 3:27 p.m. and again at 3:48 pm.

Police say a 911 operator told Silbas that she would be placed on hold temporarily, so that they could talk to Dallas Fire-Rescue about sending an ambulance.

Silbas says she hung up because she was put on hold for more than 20 minutes.

“Anything making my child hurt kills me. I felt like I was the one that got shot when I got the phone call,” she said.

Dallas police say there were several other emergency calls were holding at the time Kevin’s call came in.

“If I would have called them and said it was a police shot at -- he ain't been shot mam but he’s been shot at -- I guarantee you Mike Rawlings and everybody would have been down there,” Smith says. “They would have blocked off every street down there. They would have come up with that manpower.”